Process for carbonizing carbonaceous materials



WALLACE. PROCESS FOR CARBONIZING CARBONACEOUS MATERIALS.

APPLICATION FILED IAN.23, 1919.

Patented Nov. 9, 1920.

lill

GEORGE W. WALLACE, 0F EAST'ST. LGUES, IMZNEE.

PELCESS FR CARBNEIZENG GARBQNAGEDUS lQ/ElEl-MLS;

Specification of etterslatent.

Application filed `lanuary 23, mit). serial No. $372,767.

ln my prior lU. S. Patent No. 1,283,001,

dated Uctober 29, 1918, l have described a .process for distilling, carbonizing or vaporizing carbonaceous materials such as coals, lignites, oils and shales, which process consists in heating carbonaceous material in a closed chamber or retort and subjecting said material to such treatment that the evolved gases, vapors and liquids are removed before they can undergo secondary decomposition. This is effected by causing the evolved gases, vapors and liquids to escape from the chamber by traveling through the coolest portion of the material in the cham ber into a take-od' duct and thence immediately escape from said chamber through a suction pipe that communicates `with one end of said take-0E duct. rlhe heat is applied externally to the side Wall of the chamber or retort that holds the material, and consequently, the material therein, if fusible, becomes coked progressively, as the heat penetrates through said material, the heat causing the material to fuse into a puttylike, impervious mass, and thereafter turn into coke. As the process proceeds the coking zone, represented by the fused material, moves inwardly progressively, toward the center take-od' duct, thus leaving a body of coke in the zone outside of the coking zone, or, in other words, in the space between the heated walls of the retort and the fused mass of material that is being converted into coke.

ln using the process above referred to for the carbonization of coal, manufacture of coke and production of oil from bituminous substances which f use upon being subjected to a high temperature, l have discovered that in some instances gases continue to evolve from the material that has passed through the coking stage and that said gases produce a bach pressure in the outer zone lying beyond the colring zone. lf this bach pressure becomes relatively high the gases that are evolved in the outer zone are forced through the colring zone, thereby producing fissures or cracks in the fused mass in the colring zone.' 'lhese fissures or craclrs, when first formed, are very slight, but as the material continues to shrink as the colting operation proceeds, they open up or become wider, thereby causing the colte that is produced by the process to be fragile and in the form of small pieces. ll/loreover, the back pressure that is sometimes produced in the zone outside of the colrng zone seems to increase the time required to carbonize or distil the material in the retort.

'l'he main object of my present invention is to' provide a process for distilling, carbonizing or vaporizing solid carbonaceous materials that has the good features and characteristics of the process described in my prior patent above" referred to, namely, prevents the evolved gases, lvapors and liquids from undergoing secondary decomposition, and which insures the production of a good grade of coke, when coal is the carbonaceous material distilled, even though gases are evolved in the Zone outside of the colring zone.z

Another objectisto provide a novel apparatus for distilling, carbonizing or vaporizing solid carbonaceous material.

To this end l have devised a process which consists in heating carbonaceous material Patented Nov., 9, 31929.,

in a closed chamber or retort, withdrawing under reduced pressure the gases, vapors and liquids evolved yfrom the material in the ooking zone and causing said gases, vapors and liquids to travel through the coolest portion of the material in the chamber into a take-olf duct through which they immediately escape from the apparatus, and pre* venting a back pressure from being created in the Zone outside of the coking zone of sufiicient force to cause the gases in said outer zone to break through anddisrupt the fused material in the coking zone at the critical time in 1thefprocess at which any disturbance ofthe coking material Will have a permanent eect on the structure of the colte roduced by the process. l have also devised an apparatus for practising my process, which apparatus consists of a closed chamber or retort, a perforated take-olf duct arranged inside of said chamber and concoking zone.

' The apparatus shown in Fig. 1 vcomprises a closed chamber or retort A that is adapted to contain carbonaceous material, means for heating the side wall of said chamber, such, for example', as a combustion chamber B to which products of combustionare supplied,` a perforated take-Qd' duct C arranged preferably atthe center of the chamber A and having its lower end communicating with an eduction pipe D which is connected with a suction-producing device (not shown)` and a valve E at the upper end of the take-off duct C that opens automatically under certain conditions, and thus prevents pressure from building up in thevretort suiiciently to disru t the fused material in the coking zone.

4gVhen heat is applied to the walls of the chamber A the material'in 'saidchamber will become coked progressively as the heat penetrates inwardly through said material, the heat causing said material to first fuse vinto a putty-like, impervious ,mass and then turn into' coke. The gases, vapors and liquids that are evolved from the material during v the coking'operation are drawn into the takeoff duct C through the perforations 1 therein, and thence' travel downwardly through said ytake-off duct to the eduction pipe D vthrough which they are-.conveyed away from the apparatusffl In view of the fact that the take-off duct is'arranged at the center of the chamber Aat' the coolest part of the body of material in said chamber, and as said'take-of duct 'communicates at one endA with a suction-producing device, the gases, vapors and liquids that are 'evolved from the material which is passing through the coking stage travel through the coolest portion of the material 'in the chamber A during the operation of escaping from said chamber, thus causing a reduction in the temperature of the gases, vapors and liquids below the initial temperature 'of formation, and conse' uently, preventing any further breakin own of the hydrocarbon molecules. are immediately conducted out of the apparatus through atake-off duct which is so formed that no liquids can'co'llect andre main therein, there is no possibility of the liquids f condensing, revaporizing or .becoming cracked or mlxed wlth thematerial in wing to the fact that the liquidsl messes the chamber A that surrounds the take-off duct.

In y.the event that a back pressure is created in the Zone a outside of the coking zone represented by the mass of fused material y that is being converted into coke, the valve E in the upper end of the take-off duct C will open automatically before said back pressure reaches such a degree that it will cause the gases evolved in the zone to be forced through the fused material 'y in the coking zone, thereby automatically relieving the pressure in the portion of the chamber A between the side wall of said chamber and the'fused material in the coking zone y.

Consequently, the colte that is produced by' my Vpresent process will be firm and in the form of large pieces, as it is impossible for sufficient back pressure to be developed in the chamber A to cause the gases that are evolved in the zone to be forced through the coking zone, and thus produce fissures or cracks in the fused material y at the critical time at which any disturbance of the coking mass will have a permanent affect on the structure of the coke. The percentage of gases that are evolved in the outer Zone a is relatively small,-never in excess of iive per cent. of the total gases and vapors evolvedl from the material in the chamber A. When the relief valve E is arranged in the upper end of the take-ofi' duct, as herein shown, there is no loss of gases, as the gases which escape through the port controlled by said relief valve enter the take-off duct C. In all other respects my present process is the same as the'process described in my prior U. S. patent above referred to, as it -insures the removal of the major portion of the evolved gases, liquids and vapors in such a manner that they pass through the coolest zone in the chamber Ainescaping therefrom and are'immediately removed from the apparatus before secondary decomposition can occur, namely, before the hydrocarbon molecules inthe gases .can break down and before` the liquids can condense, revaporize, become cracked or mixed with the Vmaterial in the chamber A that surrounds the take-ofil duct.

In the apparatus shown in Fig. 1 the means for relieving the pressure that def velops in the zone outside of the coking zone consists: of a valve E that is arranged in the upper end of the take-off duct, as previously described, said valve being carried by a pivotallymounted device 2, that is equipped with a-weight 3 which normally holds the valve E seated. Various other means can be used, however, for relieving the pressure in the chamber A, and therefore, I.have illustrated in Fig. 2 of the drawings: an apparatus in which the chamber A is provided adjacent its upper end with a discharge pipe 4 that passes through Oa water seal 5 which is provided at its upper end with an outlet lessees pipe 6. ln such an apparatus the relatively.

small amount of gases that are evolved in the outer zone X escape from the upper end of the chamber A through the discharge pipe 4. In F ig. 3 of the drawings ll have shown still another way of relieving the pressure in the chamber A, the apparatus shown in F ig. 3 being provided with a spring-actuated relief valve E that 'is arl ranged in a discharge pipe 4a which leads from the upper end ofthe chamber A, said valve E being normally seated, but being capable of opening automatically so as to relieve the pressure in the chamber A in the manner previously described.

l do not wish it to be understood that the process described in my prior U. S. Patent No. 1,283,001, dated @ctober 29,1918 is inoperative or fails to produce the results describedv in said patent, for said process works perfectly .on oil shale, cannel coal and oil bearing sands. In some instances, how= ever, particularly in the production of oils and coke from coal, the resultsobtained by my said prior process are not always unia form, and it is the purpose of my present invention to make my prior process more perfect and uniform by providin means for eliminating the possibility of te ture of the coke being affected or the time required to carbonize or distil the material being increased by the gases which are someltimes evolved from the material outside of the colring zone. l

Having thus described my invention, what l claim and desire to secure by Letters Patent is:

1. A process for distilling, carbonizing or vaporizing solid carbonaceous materials, characterized by applying heat externally to a chamber in which solid carbonaceous -materia-l is arranged, 'causing the gases,

i vaporizing solid carbonaceous materials,

characterized by applying heat externally to a chamber in which solid carbonaceous material is arranged, causing the gases, vapors and liquids that are evolved from the material in the colring zone to'travel through the coolest portieri of the material in said chamber into a perforated discharge passageway' and then escape from said disn charge passageway before secondary decomm position can take glace and` before the liquids can escape om said passageway Vhaelt into said chamber and mir.' with the strucmaterial therein, and automatically relieving the pressure produced in said chamber by the gases evolved from the material outside of the coking zone.

3. A process for distilling, carbonizing or vaporizing solid carbonaceous materials, characterized by applying heat externally to a chamber in which solid carbonaceous material is arranged, withdrawing under reduced pressure the gases, vapors and liquids that are evolved from the material in the coking zone, removing said gases, vapors and liquids before they can undergo secondary decomposition in escaping lfrom the chamber, and controllinor governing the pressure that is produced in said cham ber between the 'outer wall thereof and the fused mass of material in the coking zone; for the purpose described.

4.- A process for distilling, carbonizing or vaporizing solid carbonaceous materials,

characterized by applying heat externally to a chamber'in which solid carbonaceous material is arranged, causing the gases, vapors and liquids that are evolved from the material in the coking zone to travel through the coolest portion of the ,material in said chamber into a discharge passageway, immediately removing said gases, vapors and liquids from said passageway, and permitting the gases that are evolved from the material outside of the coking zone to escape automatically before the pressure in said chamber becomes great enough to force said gases through the fused material in the cokin zone.

5. process for distilling, carbonizing or vaporizing 'solid carbonaceous material, characterized by applying heat externally to a, chamber in which solid carbonaceous material is arranged, withdrawing under reduced pressure the gases, vapors and liquids evolved from the material in the coking zone and causing them to travel through the coolest portion of the material in said chamber into a conduit through which they are immediately removed from the apparatus, and preventing the gases that are evolved in the zone outside of the coking zone from breaking vthrough the fused material in the cokingzone and thus disrupting or forming ssures in same.

, 5. A process for distilling, carbonizing or vaporizing solid carbonaceous material, characterized by applying heat externally to a chamber in which solid carbonaceous material is arranged, causing the gases, vapors and-liquids evolved from the material in the coking zone to travel through the coolest portion of the material in said chamber into a perforated takeoff duct and thence flow downwardly through said taireoH duct into a conduit through which 'they are immediately conducted away from the apparatus, and permitting some of the gases that are evolved in-the vzone outside of the coking zone to escape from said chamber from time to time, thereby preventing an abnormal back pressure from being created outside of the coking zone.

7. An apparatus for distilling, carbonizing or Vaporizing solid carbonaceous materials, comprising a chamber or retort that is adapted to receive solid carbonaceous material, a perforated take-0H duct arranged in said chamber and having its lower end communicating With a suction conduit, and a relief valve arranged adjacent the upper end of said chamber; for the purpose described. l

8. An apparatus for distilling, carbonizing or vaporizing solid carbonaceous materials, comprising a chamber or retort that is adapted to receive solid carbonaceous ma! terial, means for externally heating said chamber, means for causing the gases, va-

pors and liquids evolved from the material j ...Leashes in the. coking zone to travel through the coolest portion of the material in said cham* ber and escape from the apparatus before said gases, vapors and'liquids can undergo secondary decomposition, and means for prerials, 'comprising a chamber or retort that is adapted to receive Solid carbonaceous material, a perforated take-oli duct that constitutes the sole outlet for the gases, vapors and liquids evolved from the material in the coking zone, the lower end of said takeoff duct communicating with a suction oon.V

duit, and means for automatically relieving pressure produced nxsaid chamber by the gases evolved from the materlal outside of the coking zone.

GEORGE WALLACE 

